Author summary Microbial communities interact by competing for shared nutrients and by cross-feeding on each other’s metabolic byproducts. A widely used approach to model these dynamics is the generalized Lotka-Volterra (GLV) model, which considers only pairwise interactions, under the assumption that resources adjust much faster than populations. We tested when this simplification holds by thoroughly comparing a general resource-explicit consumer-resource model to its GLV approximation. We find that across a wide range of biologically realistic scenarios, the GLV mis-predicts which species persist, how stable the community is, and whether disturbances are amplified before settling (reactivity). These errors are amplified when cross-feeding is strong and when many species prefer similar resources (high niche overlap). The GLV’s pairwise interaction framework breaks down in such strongly coupled, cross-feeding microbial systems because resource and consumer timescales are not well separated. In such cases, tracking key resources and using hybrid modeling will yield more reliable predictions.
Introduction
Microbial communities play an integral role in ecosystems across scales, ranging from their influence on the metabolism of individual organisms [1], to whole-ecosystem biogeochemical cycling [2]. The functioning of any microbial communit… [27383 chars]
Source: PLOS (Public Library of Science) | Published: 2025-12-03T00:00:00Z
Credit: PLOS (Public Library of Science)
